U.S. patent application number 12/844788 was filed with the patent office on 2012-02-02 for system and method for tracking vital-signs monitor patches.
Invention is credited to Damitha Wilwara Arachchige, Alison Burdett, Mat Key.
Application Number | 20120029313 12/844788 |
Document ID | / |
Family ID | 45527417 |
Filed Date | 2012-02-02 |
United States Patent
Application |
20120029313 |
Kind Code |
A1 |
Burdett; Alison ; et
al. |
February 2, 2012 |
SYSTEM AND METHOD FOR TRACKING VITAL-SIGNS MONITOR PATCHES
Abstract
Systems and methods of tracking vital-sign monitor patches are
disclosed. At least one of a new wireless communication link and
loss of an existing wireless communication link between a
vital-sign monitor patch and a bridge in the monitoring network is
identified. A database comprising information indicative of
wireless communication links between vital-sign monitor patches and
bridges in the monitoring network is accessed. The information in
the database is updated to indicate the new wireless communication
link or the loss of the existing wireless communication link.
Inventors: |
Burdett; Alison; (Oxford,
GB) ; Arachchige; Damitha Wilwara; (Abingdon, GB)
; Key; Mat; (Oxford, GB) |
Family ID: |
45527417 |
Appl. No.: |
12/844788 |
Filed: |
July 27, 2010 |
Current U.S.
Class: |
600/301 |
Current CPC
Class: |
A61B 5/24 20210101; A61B
5/0022 20130101; A61B 5/0809 20130101; G16H 40/67 20180101; A61B
5/282 20210101; A61B 5/0002 20130101; A61B 5/0006 20130101; A61B
5/1113 20130101; A61B 5/0008 20130101; H04L 67/125 20130101; A61B
5/6833 20130101; A61B 2560/0412 20130101 |
Class at
Publication: |
600/301 |
International
Class: |
A61B 5/00 20060101
A61B005/00 |
Claims
1. A method of tracking vital-sign monitor patches in a vital-sign
monitoring network, the method comprising: identifying at least one
of a new wireless communication link and loss of an existing
wireless communication link between a vital-sign monitor patch and
a bridge in the monitoring network; accessing a database comprising
information indicative of wireless communication links between
vital-sign monitor patches and bridges in the monitoring network;
and updating the information in the database to indicate the new
wireless communication link or the loss of the existing wireless
communication link.
2. The method of claim 1 wherein the vital-sign monitor patch is
configured to monitor one or more of vital signs of a person to
whom the monitor patch is attached.
3. The method of claim 1, wherein identifying the new wireless
communication link comprises receiving a message from the bridge
indicating that the bridge has established the new wireless
communication link with the vital-sign monitor patch.
4. The method of claim 1, wherein identifying the loss of an
existing wireless communication link comprises receiving a message
from the bridge indicating that the bridge has lost the existing
wireless communication link with the vital-sign monitor patch.
5. A vital-sign monitoring system, comprising: a plurality of
vital-sign monitor patches configured to monitor one or more vital
signs of patients to whom the vital-sign monitor patches are
attached; a surveillance server configured to gather data relating
to the one or more vital signs of the patients from the plurality
of vital-sign monitor patches; a plurality of bridges configured to
provide data connections between the plurality of vital-sign
monitor patches and the surveillance server; and a database
configured to store information indicative of wireless
communication links between at least some of the plurality of
vital-sign monitor patches and at least some of the plurality of
bridges, wherein the database is updated to indicate a new wireless
communication link or loss of an existing wireless communication
link between a vital-sign monitor patch and a bridge.
6. The monitoring network of claim 5, wherein the one or more
vital-signs include at least one of body temperature, pulse rate,
blood pressure, and respiratory rate.
7. The system of claim 5, wherein the database is updated by the
bridge after the bridge has established the new wireless
communication link with the vital-signs patch.
8. The system of claim 5, wherein the database is updated by the
bridge after the bridge has lost an existing wireless communication
link.
9. The system of claim 5, wherein at least one bridge among the
plurality of bridges include a memory for storing a list of
vital-sign monitor patches with which the at least one bridge has
established a wireless communication link.
10. The system of claim 5, wherein the database is updated by the
surveillance server after receiving a message from the bridge
indicating that the bridge has established the new wireless
communication link with the vital-sign monitor patch.
11. The system of claim 5, wherein the database is updated by the
surveillance server after receiving a message from the bridge
indicating that the bridge has lost the existing wireless
communication link with the vital-sign monitor patch.
12. The system of claim 5, wherein at least one vital-sign monitor
patch among the plurality of vital-sign monitor patches has a
plurality of wireless communication links with two or more bridges
among the plurality of bridges.
13. The system of claim 12, wherein the surveillance server is
further configured to select one of the two or more bridges to be
associated with the at least one vital-sign monitor patch.
14. The system of claim 13, wherein the selection is based on
signal strengths of respective wireless communication links between
the at least one vital-sign monitor patch and the two or more
bridges.
15. The system of claim 13, wherein the selection is based on
numbers of respective existing associations of the two or more
bridges.
16. The system of claim 13, wherein the surveillance server is
further configured to prevent one or more unselected bridges among
the two or more bridges from communicating with the at least one
vital-sign monitor patch.
17. The system of claim 13, wherein the surveillance server is
further configured to detect loss of communication connection
between the surveillance server and the selected bridge.
18. The system of claim 17, wherein if the loss of communication
connection between the surveillance server and the selected bridge
is detected, the surveillance server is further configured to
select another bridge among the two or more bridges to be
associated with the at least one vital-sign monitor patch.
19. The system of claim 13, wherein the surveillance server is
further configured to detect loss of wireless communication link
between the selected bridge and the at least one vital-sign monitor
patch.
20. The system of claim 19, wherein if the loss of wireless
communication link between the selected bridge and the at least one
vital-sign monitor patch is detected, the surveillance server is
further configured to select another bridge among the two or more
bridges to be associated with the at least one vital-sign monitor
patch.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The following applications disclose certain common subject
matter with the present application: A Vital-Signs Monitor with
Encapsulation Arrangement, docket number 080624-0612; A Vital-Signs
Monitor with Spaced Electrodes, docket number 080624-0623; A
Vital-Signs Patch Having a Strain Relief, docket number
080624-0624; A Temperature Probe Suitable for Axillary Reading,
docket number 080624-0625; System and Method for Monitoring Body
Temperature of a Person, docket number 080624-0626; A System and
Method for Storing and Forwarding Data from a Vital-Signs Monitor,
docket number 080624-0627; System and Method for Saving Battery
Power in a Vital Signs Monitor, docket number 080624-0628; A System
and Method for Conserving Battery Power in a Patient Monitoring
System, docket number 080624-0629; A System and Method for Saving
Battery Power in a Patient Monitoring System, docket number
080624-0630; A System And Method for Reducing False Alarms
Associated with Vital-Signs Monitoring, docket number 080624-0632;
A System And Method for Location Tracking of Patients in a
Vital-Signs Monitoring System, docket number 080624-0633; A System
And Method for Reducing False Alarms Based on Motion and Location
Sensing, docket number 080624-0634; all of the listed applications
filed on ______.
FIELD
[0002] The present disclosure generally relates to systems and
methods of physiological monitoring, and, in particular, a system
and method for tracking vital-signs monitor patches.
DESCRIPTION OF THE RELATED ART
[0003] Some of the most basic indicators of a person's health are
those physiological measurements that reflect basic body functions
and are commonly referred to as a person's "vital signs." The four
measurements commonly considered to be vital signs are body
temperature, pulse rate, blood pressure, and respiratory rate. Some
clinicians consider oxygen saturation (S.sub.02) to be a "fifth
vital sign" particularly for pediatric or geriatric cases. Some or
all of these measurements may be performed routinely upon a patient
when they arrive at a healthcare facility, whether it is a routine
visit to their doctor or arrival at an Emergency Room (ER).
[0004] Vital signs are frequently taken by a nurse using basic
tools including a thermometer to measure body temperature, a
sphygmomanometer to measure blood pressure, and a watch to count
the number of breaths or the number of heart beats in a defined
period of time which is then converted to a "per minute" rate. If a
patient's pulse is weak, it may not be possible to detect a pulse
by hand and the nurse may use a stethoscope to amplify the sound of
the patient's heart beat so that she can count the beats. Oxygen
saturation of the blood is most easily measured with a pulse
oximeter.
[0005] When a patient is admitted to a hospital, it is common for
vital signs to be measured and recorded at regular intervals during
the patient's stay to monitor their condition. A typical interval
is 4 hours, which leads to the undesirable requirement for a nurse
to awaken a patient in the middle of the night to take vital sign
measurements.
[0006] When a patient is admitted to an ER, it is common for a
nurse to do a "triage" assessment of the patient's condition that
will determine how quickly the patient receives treatment. During
busy times in an ER, a patient who does not appear to have a
life-threatening injury may wait for hours until more-serious cases
have been treated. While the patient may be reassessed at intervals
while awaiting treatment, the patient may not be under observation
between these reassessments.
[0007] Measuring certain vital signs is normally intrusive at best
and difficult to do on a continuous basis. Measurement of body
temperature, for example, is commonly done by placing an oral
thermometer under the tongue or placing an infrared thermometer in
the ear canal such that the tympanic membrane, which shared blood
circulation with the brain, is in the sensor's field of view.
Another method of taking a body temperature is by placing a
thermometer under the arm, referred to as an "axillary" measurement
as axilla is the Latin word for armpit. Skin temperature can be
measured using a stick-on strip that may contain panels that change
color to indicate the temperature of the skin below the strip.
[0008] Measurement of respiration is easy for a nurse to do, but
relatively complicated for equipment to achieve. A method of
automatically measuring respiration is to encircle the upper torso
with a flexible band that can detect the physical expansion of the
rib cage when a patient inhales. An alternate technique is to
measure a high-frequency electrical impedance between two
electrodes placed on the torso and detect the change in impedance
created when the lungs fill with air. The electrodes are typically
placed on opposite sides of one or both lungs, resulting in
placement on the front and back or on the left and right sides of
the torso, commonly done with adhesive electrodes connected by
wires or by using a torso band with multiple electrodes in the
strap.
[0009] Measurement of pulse is also relatively easy for a nurse to
do and intrusive for equipment to achieve. A common automatic
method of measuring a pulse is to use an electrocardiograph (ECG or
EKG) to detect the electrical activity of the heart. An EKG machine
may use 12 electrodes placed at defined points on the body to
detect various signals associated with the heart function. Another
common piece of equipment is simply called a "heart rate monitor."
Widely sold for use in exercise and training, heart rate monitors
commonly consist of a torso band, in which are embedded two
electrodes held against the skin and a small electronics package.
Such heart rate monitors can communicate wirelessly to other
equipment such as a small device that is worn like a wristwatch and
that can transfer data wirelessly to a PC.
[0010] Nurses are expected to provide complete care to an assigned
number of patients. The workload of a typical nurse is increasing,
driven by a combination of a continuing shortage of nurses, an
increase in the number of formal procedures that must be followed,
and an expectation of increased documentation. Replacing the manual
measurement and logging of vital signs with a system that measures
and records vital signs would enable a nurse to spend more time on
other activities and avoid the potential for error that is inherent
in any manual procedure.
SUMMARY
[0011] For some or all of the reasons listed above, there is a need
to be able to continuously monitor patients in different settings.
In addition, it is desirable for this monitoring to be done with
limited interference with a patient's mobility or interfering with
their other activities.
[0012] Embodiments of the patient monitoring system disclosed
herein measure certain vital signs of a patient, which include
respiratory rate, pulse rate, blood pressure, body temperature,
and, in some cases, oxygen saturation (S.sub.O2), on a regular
basis and compare these measurements to defined limits.
[0013] In one aspect of the present disclosure, a method of
tracking vital-sign monitor patches in a vital-sign monitoring
network is provided. The method can comprise identifying at least
one of a new wireless communication link and loss of an existing
wireless communication link between a vital-sign monitor patch and
a bridge in the monitoring network. The method can further comprise
accessing a database comprising information indicative of wireless
communication links between vital-sign monitor patches and bridges
in the monitoring network. The method can further comprise updating
the information in the database to indicate the new wireless
communication link or the loss of the existing wireless
communication link.
[0014] In one aspect of the present disclosure, a vital-sign
monitoring system is provided. The system can comprise a plurality
of vital-sign monitor patches configured to monitor one or more
vital signs of patients to whom the vital-sign monitor patches are
attached. The system can further comprise a surveillance server
configured to gather data relating to the one or more vital signs
of the patients from the plurality of vital-sign monitor patches.
The system can further comprise a plurality of bridges configured
to provide data connections between the plurality of vital-sign
monitor patches and the surveillance server. The system can further
comprise a database configured to store information indicative of
wireless communication links between at least some of the plurality
of vital-sign monitor patches and at least some of the plurality of
bridges. The database can be updated to indicate a new wireless
communication link or loss of an existing wireless communication
link between a vital-sign monitor patch and a bridge.
[0015] It is understood that other configurations of the subject
technology will become readily apparent to those skilled in the art
from the following detailed description, wherein various
configurations of the subject technology are shown and described by
way of illustration. As will be realized, the subject technology is
capable of other and different configurations and its several
details are capable of modification in various other respects, all
without departing from the scope of the subject technology.
Accordingly, the drawings and detailed description are to be
regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings, which are included to provide
further understanding and are incorporated in and constitute a part
of this specification, illustrate disclosed embodiments and
together with the description serve to explain the principles of
the disclosed embodiments. In the drawings:
[0017] FIG. 1 is a diagram illustrating an exemplary embodiment of
a patient monitoring system according to certain aspects of the
present disclosure.
[0018] FIG. 2A is a perspective view of the vital-signs monitor
patch of FIG. 1 according to certain aspects of the present
disclosure.
[0019] FIG. 2B is a cross-section of the vital-signs monitor patch
of FIG. 1 according to certain aspects of the present
disclosure.
[0020] FIG. 2C is a functional block diagram illustrating exemplary
electronic and sensor components of the vital-signs monitor patch
of FIG. 1 according to certain aspects of the present
disclosure.
[0021] FIG. 3A is a functional schematic diagram of the bridge
according to certain aspects of the subject disclosure.
[0022] FIG. 3B is a functional schematic diagram of an embodiment
of the surveillance server according to certain aspects of the
present disclosure.
[0023] FIG. 4A is a map depicting a healthcare facility (e.g., a
hospital) 400 in which a patient monitoring system such as the one
shown in FIG. 1 is implemented according to certain aspects of the
present disclosure.
[0024] FIG. 4B is a portion of an exemplary database comprising
monitor patches, their linkable bridges, signal levels associated
with the communication links between the monitor patches and the
linkable bridges, and selected bridges according to certain aspects
of the present disclosure.
[0025] FIG. 5A is a map of the healthcare facility depicted in FIG.
4A after a passage of time.
[0026] FIG. 5B is a portion of an updated version of the database
shown in FIG. 4B according to certain embodiments of the present
disclosure.
[0027] FIGS. 6A-C show a first set of lists stored in various
bridge at the time of FIG. 4A, and a second set of lists which
corresponds to updated lists stored in the bridges at the time of
FIG. 5A.
[0028] FIG. 7 is a flowchart illustrating a process for tracking
locations of monitor patches by keeping and updating a database
comprising information indicative of the monitor patches and their
linkable and selected bridges according to certain aspects of the
present disclosure.
[0029] FIG. 8A is a diagram illustrating an exemplary data
structure for a message indicating a new communication link and/or
loss of an existing communication link according to certain aspects
of the present disclosure.
[0030] FIG. 8B is a diagram illustrating an exemplary data
structure for an alternative message indicating a new communication
link and/or loss of an existing communication link according to
alternative aspects of the present disclosure.
[0031] FIG. 9 is a flowchart illustrating an exemplary process for
a bridge selection process according to certain aspects of the
present disclosure.
[0032] FIG. 10 is a flowchart illustrating a process for detecting
an inoperable bridge and selecting an alternative bridge to replace
the inoperable bridge for the monitor patches that were previously
associated with the inoperable bridge according to certain aspects
of the present disclosure.
[0033] FIG. 11 is a flowchart illustrating a process for
determining locations of patients in a healthcare facility
according to certain aspects of the present disclosure.
[0034] FIG. 12A is an exemplary database comprising monitor
patches, IDs of patients assigned to the monitor patches, and names
of assigned patients according to certain aspects of the present
disclosure.
[0035] FIG. 12B is an exemplary database comprising bridges and
their respective locations within the healthcare facility according
to certain aspects of the present disclosure.
DETAILED DESCRIPTION
[0036] Periodic monitoring of patients in a hospital is desirable
at least to ensure that patients do not suffer an un-noticed sudden
deterioration in their condition or a secondary injury during their
stay in the hospital. It is impractical to provide continuous
monitoring by a clinician and cumbersome to connect sensors to a
patient, which are then connected to a fixed monitoring instrument
by wires. Furthermore, systems that sound an alarm when the
measured value exceeds a threshold value may sound alarms so often
and in situations that are not truly serious that such alarms are
ignored by clinicians.
[0037] Measuring vital signs is difficult to do on a continuous
basis. Accurate measurement of cardiac pulse, for example, can be
done using an electrocardiograph (ECG or EKG) to detect the
electrical activity of the heart. An EKG machine may use up to 12
electrodes placed at various points on the body to detect various
signals associated with the cardiac function. Another common piece
of equipment is termed a "heart rate monitor." Widely sold for use
in exercise and physical training, heart rate monitors may comprise
a torso band in which are embedded two electrodes held against the
skin and a small electronics package. Such heart rate monitors can
communicate wirelessly to other equipment such as a small device
that is worn like a wristwatch and that can transfer data
wirelessly to a personal computer (PC).
[0038] Monitoring of patients that is referred to as "continuous"
is frequently periodic, in that measurements are taken at
intervals. In many cases, the process to make a single measurement
takes a certain amount of time, such that even back-to-back
measurements produce values at an interval equal to the time that
it takes to make the measurement. For the purpose of vital sign
measurement, a sequence of repeated measurements can be considered
to be "continuous" when the vital sign is not likely to change an
amount that is of clinical significance within the interval between
measurements. For example, a measurement of blood pressure every 10
minutes may be considered "continuous" if it is considered unlikely
that a patient's blood pressure can change by a clinically
significant amount within 10 minutes. The interval appropriate for
measurements to be considered continuous may depend on a variety of
factors including the type of injury or treatment and the patient's
medical history. Compared to intervals of 4-8 hours for manual
vital sign measurement in a hospital, measurement intervals of 30
minutes to several hours may still be considered "continuous."
[0039] Certain exemplary embodiments of the present disclosure
include a system that comprises a vital-signs monitor patch that is
attached to the patient, and a bridge that communicates with
monitor patches and links them to a central server that processes
the data, where the server can send data and alarms to a hospital
system according to algorithms and protocols defined by the
hospital.
[0040] The construction of the vital-signs monitor patch is
described according to certain aspects of the present disclosure.
As the patch may be worn continuously for a period of time that may
be several days, as is described in the following disclosure, it is
desirable to encapsulate the components of the patch such that the
patient can bathe or shower and engage in their normal activities
without degradation of the patch function. An exemplary
configuration of the construction of the patch to provide a
hermetically sealed enclosure about the electronics is
disclosed.
[0041] In the following detailed description, numerous specific
details are set forth to provide a full understanding of the
present disclosure. It will be apparent, however, to one ordinarily
skilled in the art that embodiments of the present disclosure may
be practiced without some of the specific details. In other
instances, well-known structures and techniques have not been shown
in detail so as not to obscure the disclosure.
[0042] FIG. 1 discloses a vital sign monitoring system according to
certain embodiments of the present disclosure. The vital sign
monitoring system 12 includes vital-signs monitor patch 20, bridge
40, and surveillance server 60 that can send messages or interact
with peripheral devices exemplified by mobile device 90 and
workstation 100.
[0043] Monitor patch 20 resembles a large adhesive bandage and is
applied to a patient 10 when in use. It is preferable to apply the
monitor patch 20 to the upper chest of the patient 10 although
other locations may be appropriate in some circumstances. Monitor
patch 20 incorporates one or more electrodes (not shown) that are
in contact with the skin of patient 10 to measure vital signs such
as cardiac pulse rate and respiration rate. Monitor patch 20 also
may include other sensors such as an accelerometer, temperature
sensor, or oxygen saturation sensor to measure other
characteristics associated with the patient. These other sensors
may be internal to the monitor patch 20 or external sensors that
are operably connected to the monitor patch 20 via a cable or
wireless connection. Monitor patch 20 also includes a wireless
transmitter that can both transmit and receive signals. This
transmitter is preferably a short-range, low-power radio frequency
(RF) device operating in one of the unlicensed radio bands. One
band in the United States (US) is, for example, centered at 915 MHz
and designated for industrial, scientific and medical (ISM)
purposes. An example of an equivalent band in the European Union
(EU) is centered at 868 MHz. Other frequencies of operation may be
possible dependent upon the International Telecommunication Union
(ITU), local regulations and interference from other wireless
devices.
[0044] Surveillance server 60 may be a standard or virtualized
computer server connected to the hospital communication network and
preferably located in the hospital data center or computer room,
although other locations may be employed. The server 60 stores and
processes signals related to the operation of the patient
monitoring system 12 disclosed herein including the association of
individual monitor patches 20 with patients 10 and measurement
signals received from multiple monitor patches 20. Hence, although
only a single patient 10 and monitor patch 20 are depicted in FIG.
1, the server 60 is able to monitor the monitor patches 20 for
multiple patients 10.
[0045] Bridge 40 is a device that connects, or "bridges", between
monitor patch 20 and server 60. Bridge 40 communicates with monitor
patch 20 over communication link 30 operating, in these exemplary
embodiments, at approximately 915 MHz and at a power level that
enables communication link 30 to function up to a distance of
approximately 10 meters. It is preferable to place a bridge 40 in
each room and at regular intervals along hallways of the healthcare
facility where it is desired to provide the ability to communicate
with monitor patches 20. Bridge 40 also is able to communicate with
server 60 over network link 50 using any of a variety of computer
communication systems including hardwired and wireless Ethernet
using protocols such as 802.11a/b/g or 802.3af. As the
communication protocols of communication link 30 and network link
50 may be very different, bridge 40 provides data buffering and
protocol conversion to enable bidirectional signal transmission
between monitor patch 20 and server 60.
[0046] While the embodiments illustrated by FIG. 1 employ a bridge
20 to provide communication link between the monitor patch 20 and
the server 60, in certain alternative embodiments, the monitor
patch 20 may engage in direct wireless communication with the
server 60. In such alternative embodiments, the server 60 itself or
a wireless modem connected to the server 60 may include a wireless
communication system to receive data from the monitor patch 20.
[0047] In use, a monitor patch 20 is applied to a patient 10 by a
clinician when it is desirable to continuously monitor basic vital
signs of patient 10 while patient 10 is, in this embodiment, in a
hospital. Monitor patch 20 is intended to remain attached to
patient 10 for an extended period of time, for example, up to 5
days in certain embodiments, limited by the battery life of monitor
patch 20. In some embodiments, monitor patch 20 is disposable when
removed from patient 10.
[0048] Server 60 executes analytical protocols on the measurement
data that it receives from monitor patch 20 and provides this
information to clinicians through external workstations 100,
preferably personal computers (PCs), laptops, or smart phones, over
the hospital network 70. Server 60 may also send messages to mobile
devices 90, such as cell phones or pagers, over a mobile device
link 80 if a measurement signal exceeds specified parameters.
Mobile device link 80 may include the hospital network 70 and
internal or external wireless communication systems that are
capable of sending messages that can be received by mobile devices
90.
[0049] FIG. 2A is a perspective view of the vital-signs monitor
patch 20 shown in FIG. 1 according to certain aspects of the
present disclosure. In the illustrated embodiment, the monitor
patch 20 includes component carrier 23 comprising a central segment
21 and side segments 22 on opposing sides of the central segment
21. In certain embodiments, the central segment 21 is substantially
rigid and includes a circuit assembly (24, FIG. 2B) having
electronic components and battery mounted to a rigid printed
circuit board (PCB). The side segments 22 are flexible and include
a flexible conductive circuit (26, FIG. 2B) that connect the
circuit assembly 24 to electrodes 28 disposed at each end of the
monitor patch 20, with side segment 22 on the right shown as being
bent upwards for purposes of illustration to make one of the
electrodes 28 visible in this view.
[0050] FIG. 2B is a cross-sectional view of the vital-signs patch
20 shown in FIGS. 1 and 2A according to certain aspects of the
present disclosure. The circuit assembly 24 and flexible conductive
circuit 26 described above can be seen herein. The flexible
conductive circuit 26 operably connects the circuit assembly 24 to
the electrodes 28. Top and bottom layers 23 and 27 form a housing
25 that encapsulate circuit assembly 28 to provide a water and
particulate barrier as well as mechanical protection. There are
sealing areas on layers 23 and 27 that encircles circuit assembly
28 and is visible in the cross-section view of FIG. 2B as areas 29.
Layers 23 and 27 are sealed to each other in this area to form a
substantially hermetic seal. Within the context of certain aspects
of the present disclosure, the term `hermetic` implies that the
rate of transmission of moisture through the seal is substantially
the same as through the material of the layers that are sealed to
each other, and further implies that the size of particulates that
can pass through the seal are below the size that can have a
significant effect on circuit assembly 24. Flexible conductive
circuit 26 passes through portions of sealing areas 29 and the seal
between layers 23 and 27 is maintained by sealing of layers 23 and
27 to flexible circuit assembly 28. The layers 23 and 27 are thin
and flexible, as is the flexible conductive circuit 26, allowing
the side segment 22 of the monitor patch 20 between the electrodes
28 and the circuit assembly 24 to bend as shown in FIG. 2A.
[0051] FIG. 2C is a functional block diagram 200 illustrating
exemplary electronic and sensor components of the monitor patch 20
of FIG. 1 according to certain aspects of the present disclosure.
The block diagram 200 shows a processing and sensor interface
module 201 and external sensors 232, 234 connected to the module
201. In the illustrated example, the module 201 includes a
processor 202, a wireless transceiver 207 having a receiver 206 and
a transmitter 209, a memory 210, a first sensor interface 212, a
second sensor interface 214, a third sensor interface 216, and an
internal sensor 236 connected to the third sensor interface 216.
The first and second sensor interfaces 212 and 214 are connected to
the first and second external sensors 232, 234 via first and second
connection ports 222, 224, respectively. In certain embodiments,
some or all of the aforementioned components of the module 201 and
other components are mounted on a PCB.
[0052] Each of the sensor interfaces 212, 214, 216 can include one
or more electronic components that are configured to generate an
excitation signal or provide DC power for the sensor that the
interface is connected to and/or to condition and digitize a sensor
signal from the sensor. For example, the sensor interface can
include a signal generator for generating an excitation signal or a
voltage regulator for providing power to the sensor. The sensor
interface can further include an amplifier for amplifying a sensor
signal from the sensor and an analog-to-digital converter for
digitizing the amplified sensor signal. The sensor interface can
further include a filter (e.g., a low-pass or bandpass filter) for
filtering out spurious noises (e.g., a 60 Hz noise pickup).
[0053] The processor 202 is configured to send and receive data
(e.g., digitized signal or control data) to and from the sensor
interfaces 212, 214, 216 via a bus 204, which can be one or more
wire traces on the PCB. Although a bus communication topology is
used in this embodiment, some or all communication between discrete
components can also be implemented as direct links without
departing from the scope of the present disclosure. For example,
the processor 202 may send data representative of an excitation
signal to the sensor excitation signal generator inside the sensor
interface and receive data representative of the sensor signal from
the sensor interface, over either a bus or direct data links
between processor 202 and each of sensor interface 212, 214, and
216.
[0054] The processor 202 is also capable of communication with the
receiver 206 and the transmitter 209 of the wireless transceiver
207 via the bus 204. For example, the processor 202 using the
transmitter and receiver 209, 206 can transmit and receive data to
and from the bridge 40. In certain embodiments, the transmitter 209
includes one or more of a RF signal generator (e.g., an
oscillator), a modulator (a mixer), and a transmitting antenna; and
the receiver 206 includes a demodulator (a mixer) and a receiving
antenna which may or may not be the same as the transmitting
antenna. In some embodiments, the transmitter 209 may include a
digital-to-analog converter configured to receive data from the
processor 202 and to generate a base signal; and/or the receiver
206 may include an analog-to-digital converter configured to
digitize a demodulated base signal and output a stream of digitized
data to the processor 202.
[0055] The processor 202 may include a general-purpose processor or
a specific-purpose processor for executing instructions and may
further include a memory 219, such as a volatile or non-volatile
memory, for storing data and/or instructions for software programs.
The instructions, which may be stored in a memory 219 and/or 210,
may be executed by the processor 202 to control and manage the
wireless transceiver 207, the sensor interfaces 212, 214, 216, as
well as provide other communication and processing functions.
[0056] The processor 202 may be a general-purpose microprocessor, a
microcontroller, a Digital Signal Processor (DSP), an Application
Specific Integrated Circuit (ASIC), a Field Programmable Gate Array
(FPGA), a Programmable Logic Device (PLD), a controller, a state
machine, gated logic, discrete hardware components, or any other
suitable device or a combination of devices that can perform
calculations or other manipulations of information.
[0057] Information, such as program instructions, data
representative of sensor readings, preset alarm conditions,
threshold limits, may be stored in a computer or processor readable
medium such as a memory internal to the processor 202 (e.g., the
memory 219) or a memory external to the processor 202 (e.g., the
memory 210), such as a Random Access Memory (RAM), a flash memory,
a Read Only Memory (ROM), a Programmable Read-Only Memory (PROM),
an Erasable PROM (EPROM), registers, a hard disk, a removable disk,
or any other suitable storage device.
[0058] In certain embodiments, the internal sensor 236 can be one
or more sensors configured to measure certain properties of the
processing and sensor interface module 201, such as a board
temperature sensor thermally coupled to a PCB. In other
embodiments, the internal sensor 236 can be one or more sensors
configured to measure certain properties of the patient 10, such as
a motion sensor (e.g., an accelerometer) for measuring the
patient's motion or position with respect to gravity.
[0059] The external sensors 232, 234 can include sensors and
sensing arrangements that are configured to produce a signal
representative of one or more vital signs of the patient to which
the monitor patch 20 is attached. For example, the first external
sensor 232 can be a set of sensing electrodes that are affixed to
an exterior surface of the monitor patch 20 and configured to be in
contact with the patient for measuring the patient's respiratory
rate, and the second external sensor 234 can include a temperature
sensing element (e.g., a thermocouple or a thermistor or resistive
thermal device (RTD)) affixed, either directly or via an
interposing layer, to skin of the patient 10 for measuring the
patient's body temperature. In other embodiments, one or more of
the external sensors 232, 234 or one or more additional external
sensors can measure other vital signs of the patient, such as blood
pressure, pulse rate, or oxygen saturation.
[0060] FIG. 3A is a functional block diagram illustrating exemplary
electronic components of bridge 40 of FIG. 1 according to one
aspect of the subject disclosure. Bridge 40 includes a processor
310, radio 320 having a receiver 322 and a transmitter 324, radio
330 having a receiver 332 and a transmitter 334, memory 340,
display 345, and network interface 350 having a wireless interface
352 and a wired interface 354. In some embodiments, some or all of
the aforementioned components of module 300 may be integrated into
single devices or mounted on PCBs.
[0061] Processor 310 is configured to send data to and receive data
from receiver 322 and transmitter 324 of radio 320, receiver 332
and transmitter 334 of radio 330 and wireless interface 352 and
wired interface 354 of network interface 350 via bus 314. In
certain embodiments, transmitters 324 and 334 may include a radio
frequency signal generator (oscillator), a modulator, and a
transmitting antenna, and the receivers 322 and 332 may include a
demodulator and antenna which may or may not be the same as the
transmitting antenna of the radio. In some embodiments,
transmitters 324 and 334 may include a digital-to-analog converter
configured to convert data received from processor 310 and to
generate a base signal, while receivers 322 and 332 may include
analog-to-digital converters configured to convert a demodulated
base signal and sent a digitized data stream to processor 310.
[0062] Processor 310 may include a general-purpose processor or a
specific-purpose processor for executing instructions and may
further include a memory 312, such as a volatile or non-volatile
memory, for storing data and/or instructions for software programs.
The instructions, which may be stored in memories 312 or 340, may
be executed by the processor 310 to control and manage the
transceivers 320, 330, and 350 as well as provide other
communication and processing functions.
[0063] Processor 310 may be a general-purpose microprocessor, a
microcontroller, a Digital Signal Processor (DSP), an Application
Specific Integrated Circuit (ASIC), a Field Programmable Gate Array
(FPGA), a Programmable Logic Device (PLD), a controller, a state
machine, gated logic, discrete hardware components, or any other
suitable device or a combination of devices that can perform
calculations or other manipulations of information.
[0064] Information such as data representative of sensor readings
may be stored in memory 312 internal to processor 310 or in memory
340 external to processor 310 which may be a Random Access Memory
(RAM), flash memory, Read Only Memory (ROM), Programmable Read Only
Memory (PROM), Erasable Programmable Read Only Memory (EPROM),
registers, a hard disk, a removable disk, a Solid State Memory
(SSD), or any other suitable storage device.
[0065] Memory 312 or 340 can also store a list or a database of
established communication links and their corresponding
characteristics (e.g., signal levels) between the bridge 40 and its
related monitor patches 20. In the illustrated example of FIG. 3A,
the memory 340 external to the processor 310 includes such a
database 342; alternatively, the memory 312 internal to the
processor 310 may include such a database.
[0066] FIG. 3B is a functional block diagram illustrating exemplary
electronic components of server 60 of FIG. 1 according to one
aspect of the subject disclosure. Server 60 includes a processor
360, memory 370, display 380, and network interface 390 having a
wireless interface 392 and a wired interface 394. Processor 360 may
include a general-purpose processor or a specific-purpose processor
for executing instructions and may further include a memory 362,
such as a volatile or non-volatile memory, for storing data and/or
instructions for software programs. The instructions, which may be
stored in memories 362 or 370, may be executed by the processor 360
to control and manage the wireless and wired network interfaces
392, 394 as well as provide other communication and processing
functions.
[0067] Processor 360 may be a general-purpose microprocessor, a
microcontroller, a Digital Signal Processor (DSP), an Application
Specific Integrated Circuit (ASIC), a Field Programmable Gate Array
(FPGA), a Programmable Logic Device (PLD), a controller, a state
machine, gated logic, discrete hardware components, or any other
suitable device or a combination of devices that can perform
calculations or other manipulations of information.
[0068] Information such as data representative of sensor readings
may be stored in memory 362 internal to processor 360 or in memory
370 external to processor 360 which may be a Random Access Memory
(RAM), flash memory, Read Only Memory (ROM), Programmable Read Only
Memory (PROM), Erasable Programmable Read Only Memory (EPROM),
registers, a hard disk, a removable disk, a Solid State Memory
(SSD), or any other suitable storage device.
[0069] Memory 362 or 370 can also store a database of communication
links and their corresponding characteristics (e.g., signal levels)
between monitor patches 20 and bridges 40. In the illustrated
example of FIG. 3B, the memory 370 external to the processor 360
includes such a database 372; alternatively, the memory 362
internal to the processor 360 may include such a database.
[0070] FIG. 4A is a map depicting an exemplary healthcare facility
(e.g., a hospital) 400 in which a patient monitoring system such as
shown in FIG. 1 is implemented. The healthcare facility 400
includes a plurality of patient rooms 410A-H and hallways 420A,
420B. Shown in the map are a plurality of vital-sign monitor
patches 20A-O attached to their respectively assigned patients
10A-O located in the patient rooms 410A-H and hallways 420A, 420B.
For ease of illustration and understanding, each patient with
attached patch is represented by s triangle in FIG. 4A. The
facility 400 also includes a plurality of bridges 40A-O located at
specified locations in the facility 400 and configured to engage in
wireless communication with the monitor patches 20A-O. The bridges
40A-O are represented has circle icons. Although there are other
patient rooms, bridges, and patients/monitor patches shown in the
map, for the sake of simplicity, the following description will
focus on the patient rooms 410A-H, bridges 40A-O and
patients/monitor patches 10A-O/20A-O. In the illustrated example,
the bridges 40A-O are in turn connected to WiFi access points 45A-D
(shown as "stars") that are configured to route data between the
bridges 40A-O and a surveillance server 60 (FIG. 1).
[0071] Preferably, a bridge 40 is selected for each monitor patch
20 through which the monitor patch 20 sends and receives signals to
and from the server 60 via an access point 45A,B,C, or D. For
example, the monitor patch 20B worn by the patient 10B in the room
41013 wirelessly transmits one or more signals comprising
information indicative of his vital signs (e.g., heart rate) to the
bridge 40B. The bridge 40B receives the signals and sends the
information extracted from the signals to the access point 45 as
data via either a wired or wireless connection. The access point
45A sends the data to the surveillance server 60 via either a wired
or wireless connection. As other examples, the monitor patch 20A
worn by the patient 10A in the room 410A sends data to the server
60 via the bridge 60A and the access point 45A; the monitor patch
20P worn by the patient 10P, walking eastward in the hallway 420A,
sends data to the server 60 via the bridge 40N and the access point
45A; and the monitor patch 20M worn by the patient 10M, walking
southward in the hallway 420B, sends data to the server 60 via the
bridge 40J and the access point 45D.
[0072] Because a monitor patch 20 and a bridge 40 have limited
wireless ranges, the monitor patch 20 is located in close proximity
from the bridge 40 with which the monitor patch has a communicative
association. Therefore, it is possible to track the location of a
monitor patch 20 by knowing the location of the selected bridge 40.
In certain embodiments of a monitoring network of the present
disclosure, the surveillance server 60 is configured to track
locations of the monitor patches 20A-O by maintaining a database
comprising information indicative of monitor patches 20A-O and
their selected bridges 40A-O. In certain embodiments, the database
further comprises a list of unselected but linkable bridges with
which each of the monitor patches 20A-O is capable of engaging in a
bidirectional wireless data communication.
[0073] FIG. 4B is a portion of an exemplary database comprising the
monitor patches 20A-20P (first column), their linkable bridges
(second column), signal levels associated with the communication
links between the monitor patches and the linkable bridges (third
column) in an arbitrary unit (e.g., dbm), and selected bridges
(fourth column) according to certain aspects of the present
disclosure. Such a database may be stored in the memory 370 (FIG.
3B) of the server 60 as database 372, for example. Alternatively,
the database may be stored in a memory located outside the server
60 (e.g., on a network) but accessible by the server 60 via, e.g.,
a wired or wireless interface 992, 994. For ease of illustration,
it is assumed that the database of FIG. 4B corresponds to the
database 372 of FIG. 3B.
[0074] For example, the database 372 shows the monitor patch 20A
having one linkable bridge 40A which is also the selected bridge.
The database 372 also shows the monitor patches 20B and 20C having
the same linkable bridges 40B, 40C of which the bridges 40B is the
selected bridge for the both monitor patches. The database 372 also
shows the monitor patch 20D having the same linkable bridges 40B,
40C of which the bridge 40C is the selected bridge. The above
portions of the database 372 relating to the monitor patches 20B-D
reflect the fact that the monitor patches 20B, 20C are in the room
410B having the bridge 40B located therein, while the monitor patch
20D is in the room 410C having the bridge 40C located therein.
Therefore, while the bridge 40B is capable of communicating with
the monitor patch 20D due to their close proximity, the bridge 40C
is selected for the monitor patch 20D, e.g., by the server 60, due
to the bridge's closer proximity to the monitor patch 20D. The
database 372 also shows the monitor patch 20M worn by the patient
10M having three linkable bridges 40I, 40J, 40K of which the bridge
40J is the currently selected bridge; and the monitor patch 20P
worn by the patient 10P having two linkable bridges 40C, 40N of
which the bridge 40N is the currently selected bridge.
[0075] The signal levels (third column) associated with various
bridge-patch communication links in the database 372 represent the
strengths of wireless signals (e.g., acknowledgment signals) from
the bridges 40A-O received by the monitor patches 20A-O. As will be
described below with respect to FIG. 9, the signal levels can be
used for a bridge selection by the surveillance server 60.
[0076] FIG. 5A is a map of the exemplary healthcare facility 400
depicted in FIG. 4A after a passage of time from the map of FIG.
4A. The map of FIG. 4B is the same as the map of FIG. 4A except for
the following changes: [0077] 1) The patient 10A wearing the
monitor patch 20A has left the facility 400. [0078] 2) The patient
10M wearing the monitor patch 20M has now returned to her patient
room 410G. [0079] 3) The patient 10P wearing the monitor patch 20P
and walking along the hallway 420A has now progressed to the middle
of the hallway 420A.
[0080] In response to the changes, the surveillance server 60 has
updated the database 372 discussed above with respect to FIG. 4B.
FIG. 5B is a portion of an updated version of the database 372
shown in FIG. 4B according to certain embodiments of the present
disclosure. The updated database 372 shows the monitor patch 20A
having neither a linkable bridge nor a selected bridge, reflecting
the fact that the monitor patch 20A is longer in communication
range of any of the bridges in the monitoring system. The updated
database also shows the monitor patch 20M now having three linkable
bridges 40H, 40I, 40K of which the bridge 40I is the currently
selected bridge, reflecting the fact that the monitor patch 20M is
now in the room 410G having the bridge 40I located therein. The
updated database also shows the monitor patch 20P having two
linkable bridges 40N, 40O of which the bridge 40O is the currently
selected bridge. In the illustrated example of FIG. 5A, the monitor
patch 20P is substantially equidistant from both the bridge 40N and
the bridge 40O and the respective signal strengths are similar (19
versus 17). Hence, the monitor patch 20P can be served equally well
by both bridges 40N, 40O. Notwithstanding the fact that the signal
strength associated with the bridge 40N is slightly higher than
that associated with the bridge 40O, control software in the
surveillance server 60 has selected the bridge 40O based on the
consideration that the monitor patch 20P worn by the patient 10P
has been moving towards the bridge 40O and away from the bridge 40N
and, hence, is likely to be served longer by the former bridge 40O
than by the latter bridge 40N.
[0081] Henceforth, specific reference numbers (e.g., bridge 40A,
monitor patch 20C) will be used when referring to specific devices,
while generic references (bridge 40, monitor patch 20) will be used
when referring to devices in a general sense.
[0082] A communication link between a bridge 40 and a monitor patch
associated 20 associated with a patient can be considered
established, for example, when the bridge 40 has received one or
more regularly transmitted signals (e.g., those indicative of vital
signs of the patient) from the monitor patch 20 or when the bridge
40 has received an acknowledgment signal from the bridge 40 in
response to a query signal sent out via the bridge 40. From the
perspective of the monitor patches 20, the bridge is one of
linkable bridges for the monitor patches 20. Conversely, an
established communication link between a bridge 40 and a monitor
patch 20 can be considered lost when the bridge 40 can no longer
receive regularly transmitted signals from the monitor patch 20 or
when the bridge 40 does not receive an acknowledgment signal from
the monitor patch 20 in response to a query signal.
[0083] In certain embodiments, upon occurrence of a new
communication link or loss of an existing communication link, the
bridge 40 automatically sends the message to the surveillance
server 60 (FIG. 1), which, in turn, updates the database 372 stored
in memory (e.g., 370) associated with the server 60, such as a hard
disk or an external data storage device accessible by the server.
In some embodiments, each of the bridges 40A-O includes memory
(e.g., 312, 340 of FIG. 3A) for storing a list or database 342 of
monitor patches 20A-O with which the bridge 40 has established
communication links. A processor (e.g., 310 of FIG. 3A) executing
control software in the bridge 40 can update the list 342 stored in
the memory (e.g., 312, 340) of the bridge 40 to keep the list
current. The processor 310 then sends the updated list 342 or a
portion thereof to the surveillance server 60.
[0084] FIG. 6A shows a first list 610A stored in the bridge 40A at
the time of FIG. 4A, and a second list 620A which corresponds to an
updated list stored in the bridge 40A at the time of FIG. 5A. The
first column of the first list 610A enumerates linkable patches
corresponding to all monitor patches with which the bridge 40A has
established communication links at the time of FIG. 4A. The second
column of the first list 610A enumerates associated patches
corresponding to all monitor patches 20 for which the bridge 40A
has been selected for communicative association at the time of FIG.
4A. As can be seen from FIG. 4A and correspondingly reflected in
the first list 610A, the bridge 40A has an established
communication link only with the monitor patch 20A. The bridge 40A
is also the selected bridge 40 for the monitor patch 20A, or,
conversely, the monitor patch 20A is an associated patch for the
bridge 40A. As can be seen from FIG. 5A and correspondingly
reflected in the second list 620A, the bridge 40A has neither a
linkable patch nor an associated patch at the time of FIG. 5A,
reflecting the fact that between the time of FIG. 4A and the time
of FIG. 5A, the patient 10A wearing the monitor patch 20A has left
the healthcare facility 400, or the patch 20A has been removed and
deactivated.
[0085] FIG. 6B shows a first list 610B stored in the bridge 40I at
the time of FIG. 4A, and a second list 620B that corresponds to an
updated list stored in the bridge 40I at the time of FIG. 5A. As
can be seen from FIG. 4A and correspondingly reflected in the first
list 610B, the bridge 40A has established communication links with
the monitor patches 20K and 20L of which the monitor patch 20L is
the associated patch. As can be seen from FIG. 5A and
correspondingly reflected in the second list 620B, the bridge 40I
has established communication links with the monitor patches 20K,
20L, and 20M of which the monitor patches 20L and 20M are the
associated patches at the time of FIG. 5A, reflecting the fact that
between the time of FIG. 4A and the time of FIG. 5A, the patient
10M wearing the monitor patch 20M has entered the patient room
410G.
[0086] FIG. 6C shows a first list 610C stored in the bridge 40N at
the time of FIG. 4A, and a second list 620C which corresponds to an
updated list stored in the bridge 40N at the time of FIG. 5A. As
can be seen from FIG. 4A and correspondingly reflected in the first
list 610B, the bridge 40N has established communication links with
the monitor patches 20F and 20P of which the monitor patch 20P is
the associated patch. As can be seen from FIG. 5A and
correspondingly reflected in the second list 620B, the bridge 40N
has established communication links with the monitor patches 20,
but has no associated patch, reflecting the condition that between
the time of FIG. 4A and the time of FIG. 5A, the patient 10P
wearing the monitor patch 20P has progressed to the center of the
hallway 420A towards the bridge 40O and the surveillance server 60
has selected the bridge 40O for the monitor patch 20P as discussed
above with respect to FIG. 5B.
[0087] FIG. 7 is a flowchart illustrating a process 700 for
tracking locations of monitor patches 20 by keeping and updating a
database comprising information indicative of the monitor patches
20 and their linkable and selected bridges 40 according to certain
aspects of the present disclosure. For the purposes of illustration
only, without any intent to limit the scope of the present
disclosure in any way, the process 700 will be described with
reference to FIGS. 1, 4A-B, and 5A-B. The process 700 begins at
start state 701 and proceeds to operation 710 in which a
surveillance server 60 receives a message from a bridge 40
indicating that the bridge 40 has established a new communication
link with a monitor patch 20 or lost an existing communication link
with a monitor patch 20 or both. For example, if the message were
sent from the bridge 40A of FIGS. 4A and 5A, the message would
indicate loss of an existing communication link with the monitor
patch 20A. On the other hand, if the message were sent from the
bridge 40I, the message would indicate a new (previously
unavailable) communication link with the monitor patch 20M.
[0088] FIG. 8A is a diagram illustrating an exemplary data
structure for a message 800A indicating a new communication link
and/or loss of an existing communication link according to certain
aspects of the present disclosure. In the illustrated example, the
message 800A includes a header field 810A for storing a message
header, an ID field 820A for storing an ID for a bridge sending the
message, a data field 830A for storing information relating to a
new communication link and/or loss of an existing communication
link, and optionally a field 840 for storing a checksum. The header
field 810A can include subfields for indicating a total number of
monitor patches with which the bridge has established new
communication links and a total number of monitor patches with
which the bridge has lost existing communication links. The data
field 830A includes a first subfield 832A for storing an ID for a
monitor patch that the bridge has established a new communication
link, a second subfield 833A for storing data indicative of a
signal level or strength associated with the new communication
link, and a third subfield 836A for storing an ID for a monitor
patch with which the bridge has lost an existing communication
link. If the message 800A were sent from the bridge 40A while
transitioning from the configuration of FIG. 4A to the
configuration of FIG. 5A, the ID field 820 would include data
indicative of the bridge 40A, and the third subfield 836A would
include data indicative of the monitor patch 20A. The message
embodiment shown in FIG. 8A is exemplary only, as other message
embodiments may be employed. The surveillance server 60 upon
receiving the message 830A can update the database such as the one
shown in FIG. 4B as further described below.
[0089] FIG. 8B is a diagram illustrating an exemplary data
structure for an alternative message 800B indicating a new
communication link and/or loss of an existing communication link
according to alternative aspects of the present disclosure. In the
illustrated example, the message 820B includes a header field 810B
for storing a message header, an ID field 820B for storing an ID
for a bridge sending the message, a data field 830B for storing
information relating to all monitor patches with which the bridge
has established communication links, and a field 840B for storing a
checksum. The header field 810A can include subfields for
indicating a total number of linkable monitor patches 20 with which
the bridge 40 has established communication links. The data field
830B includes a first subfield 8328 for storing an ID of a first
linkable monitor patch 20, a second subfield 833B for storing data
indicative of a signal strength or level associated with the
communication link between the bridge 40 and the first linkable
monitor patch 20. The data field 830B includes other subfields
834B, 835B, 836B, 837B for storing ID's and data indicative signal
strengths for additional linkable monitor patches 20. If the
message were sent from the bridge 40I in the configuration of FIG.
5A (corresponding to the list 620B of FIG. 6B), the data fields
832B, 834B, 836B would include data indicative of the monitor
patches 20K, 20L, 20M, respectively, for example. In certain
embodiments, each of the subfields 832B, 834B, 836B includes a
single bit for indicating whether the monitor patch 20 indicated by
the subfield is associated with the bridge 40 or not (i.e., whether
the bridge 40 is the selected bridge 40 for the monitor patch 20),
In those embodiments, such a bit would be clear for the subfield
832B (for the monitor patch 20K), but set for the subfields 834B,
836B (for the monitor patches 20L, 20M). The message embodiment of
FIG. 8A is exemplary only, as other message embodiments may be
employed. The surveillance server 60, upon receiving the message
830B, can update the database such as the one shown in FIG. 4B as
further described below.
[0090] Returning to FIG. 7, the process 700 proceeds to decision
state 720 in which it is determined whether the received message
indicates that the bridge 40 sending the message has established at
least one new communication link with a monitor patch 20, e.g., by
starting to receive regularly transmitted signals from the monitor
patch. In case of the message 800A of FIG. 8A, this determination
can involve control software running in a processor of the
surveillance server 60 searching for nonzero data in the data field
832A ("NEW PATCH ID"). In case of the message 800B of FIG. 8B, this
determination can involve the control software comparing the
linkable monitor patches 20 indicated in the data field 830B of the
message 800B to previously stored linkable monitor patches 20 for
the bridge 40 in order to discover one or more monitor patches 20
that are newly present in the message. If it is determined at the
state 720 that no new communication link has been established for
the bridge 40 (NO), the process 700 proceeds to decision state 730
to be described below.
[0091] On the other hand, if it is determined at the decision state
720 that at least one new communication link has been established
for the bridge 40 (YES), the process 700 proceeds to operation 725
in which database 372 comprising information indicative of
communication links between monitor patches 20A-O and bridges 40A-O
is accessed and the new communication link is added to the
database. Examples of such additions include the communication
links between the monitor patch 20M and the bridge 40I and the
communication link between the monitor patch 20P and the bridge
40O, both of which are not present in the database shown in FIG. 4A
but present in the updated database shown in FIG. 5B. The process
700 then proceeds to decision state 730 described below.
[0092] In the decision state 730 it is determined whether the
received message indicates that the bridge 40 sending the message
has lost at least one existing communication link with a monitor
patch 20, e.g., by failing to receive regularly transmitted signals
from the monitor patch 20. In case of the message 800A of FIG. 8A,
this determination can involve control software running in a
processor of the surveillance server 60 looking for nonzero data in
the subfield 836A. In case of the message 800B of FIG. 8B, this
determination can involve the control software comparing the
linkable monitor patches 20 indicated in the data field 830B of the
message 800B to previously stored linkable monitor patches 20 for
the bridge 40 in order to discover one or more monitor patches 20
that are not longer present in the message.
[0093] If it is determined at the decision state 730 that no
existing communication link has been lost for the bridge 40 (NO),
the process 700 ends at state 703. On the other hand, if it is
determined at the decision state 730 that at least one existing
communication link has been lost for the bridge (YES), the process
700 proceeds to operation 725 in which a database comprising
information indicative of communication links between monitor
patches 20A-O and bridges 40A-O is accessed and the communication
link is deleted from the database. Examples of such deletion
include the communication link between the monitor patch 20M and
the bridge 40J and the communication link between the monitor patch
20P and the bridge 40C, which is present in the database shown in
FIG. 5A but not present in the updated database shown in FIG. 5B.
The process 700 ends at state 703.
[0094] Therefore, the surveillance server 60, by maintaining and
updating a database of bridge-patch communication links using a
process such as the process 700 based on messages received from
bridges 40, can track locations of monitor patches 20A-O in the
healthcare facility 400. In certain embodiments, the surveillance
server 60, after receiving one or more of such messages or at
scheduled intervals, can select a particular bridge 40 among a set
of linkable bridges 40 for a particular monitor patch 20. After
such a bridge selection, in certain embodiments, the server 60
prevents other linkable but unselected bridges 40 from
communicating with the particular monitor patch 20.
[0095] FIG. 9 is a flowchart illustrating an exemplary process 900
for a bridge selection process according to certain aspects of the
present disclosure. The process 900 begins at start state 901 and
proceeds to decision state 910 in which it is determined whether
there are multiple bridge-patch communication links (e.g., multiple
linkable bridges) available for a particular monitor patch 20. If
it is determined at the decision state 910 that there is only one
communication link (e.g., one linkable bridge) available for the
monitor patch, the process 900 proceeds to another decision state
930 to be described below. On the other hand, if it is determined
at the decision state 910 that there are multiple communication
links (e.g., multiple linkable bridges 40) for the monitor patch
20, the process 900 proceeds to operation 920 in which signal
strengths of the multiple communication links are compared, and a
bridge 40 associated with the highest signal strength is
identified. For example, in case of the monitor patch 20M in the
configuration of FIG. 4B, the communication link between the
monitor patch 20M and the bridge 40J has the highest signal
strength (19) among all available communication links.
[0096] The process 900 proceeds to decision state 930 in which it
is determined whether the bridge 40 being considered for selection
(e.g., the only bridge in case of one communication link or the
identified bridge in case of multiple communication links) is
available for communication with the monitor patch 20. This
determination can involve determining by the surveillance server 60
or by the bridge 40 the number of monitor patches 20 with which the
bridge 40 is currently associated (e.g., the number of monitor
patches to which the bridge is currently the selected bridge) in
order to determine whether the bridge 40 is currently overloaded.
If it is determined at the decision state 930 that the bridge 40
being considered for selection is not available (NO), the process
900 proceeds to decision state 940 in which it is determined
whether there are one or more other linkable bridges 40 with which
the monitor patch 20 can be associated. If it is determined at the
decision state 940 that there is no other linkable bridge 40 (NO),
the process 900 ends at state 903. On the other hand, if it is
determined at the decision state 940 that there are one or more
other linkable bridges 40 (YES), the process 900 proceeds to
operation 945 in which another linkable bridge 40 associated with
the next highest signal strength is identified, and then back to
the decision state 930 for determining availability of the other
bridge 40.
[0097] On the other hand, if it is determined at the decision state
930 that the bridge 40 being considered for selection is available
(YES), the process 900 proceeds to decision state 950 in which it
is determined whether the selection of the bridge 40 being
considered is consistent with other considerations. For example, as
indicated above with respect to FIG. 5B, control software running
in the surveillance server 60 selected the bridge 40O over the
bridge 40N in spite of the condition that the signal strength
associated with the bridge 40N is currently stronger than the
signal strength associated with the bridge 40O. The selection is
based on the additional consideration that the patch 20P has been
moving away from the bridge 40N and towards the bridge 40O.
[0098] If it is determined at the decision state 930 that the
selection of the bridge 40 is not consistent with other
considerations (NO), the process 900 proceeds to the decision state
940 and to the operation 945 and back to the decision state 930 as
discussed above. On the other hand, if it is determined at the
decision state 930 that the selection of the bridge 40 is
consistent with other considerations (YES), the process 900
proceeds to operation 960 in which the bridge 40 is selected for
the monitor patch 20 and, the database of bridge-patch
communication links is updated to reflect the new selection. The
process 900 ends at state 903.
[0099] At times, a bridge 40 can lose power or break down or
otherwise become inoperable and can no longer carry data between
associated monitor patches 20 and the surveillance server 60. For
example, if the bridge 40I becomes inoperable, the monitor patches
20L and 20M can no longer send data to the surveillance server 60
via the bridge 40I. In certain embodiments, the surveillance server
60, upon recognition of such an occurrence, selects alternative
bridges 40 for the monitor patches 20 so as to route data between
the monitor patches 20 and the surveillance server 60 via the
alternative bridges 40.
[0100] FIG. 10 is a flowchart illustrating a process 1000 for
detecting an inoperable bridge 40 and selecting an alternative
bridge 40 to replace the inoperable bridge 40 for the monitor
patches 20 that were previously associated with the inoperable
bridge 40 according to certain aspects of the present disclosure.
The process 1000 begins at start state 1001 and proceeds to
decision state 1010 in which it is determined whether an inoperable
selected bridge 40 has been detected. The determination can include
failing to receive regularly transmitted messages from the selected
bridge 40 or failing to receive an acknowledgment message from the
bridge 40 in response to a query message sent to the bridge 40 by
the surveillance server 60. If it is determined at the decision
state 1010 that an inoperable selected bridge 40 has not been
detected (NO), the process 1000 loops back to the decision state
1010 to await such an occurrence. On the other hand, if an
inoperable selected bridge 40 has been detected (YES), the process
1000 proceeds to operation 1020 in which a monitor patch 20
associated with the selected bridge 40 is identified from, e.g.,
database (e.g., 372) such as the ones shown in FIGS. 4B and 5B. For
example, if the selected bridge found to be inoperable is the
bridge 40D, the monitor patch 20E can be identified. After the
identification, the process proceeds to decision state 1030.
[0101] In the decision state 1030, it is determined whether there
are one or more alternative linkable bridges 40 for the identified
monitor patch from, e.g., a list in a database such as the ones
shown in FIGS. 4B and 5B. If it is determined at the decision state
1030 that there is no alternative bridge 40 (NO), the process 1000
proceeds to decision state 1050 which will be described below. On
the other hand, if it is determined at the decision state 1030 that
there are one or more alternative linkable bridges 40 for the
identified monitor patch (YES) (the bridge 40B for the monitor
patch 20E in the above example), the process 1000 proceeds to
operation 1040 in which a bridge selection process such as the one
described above with respect to FIG. 9 is performed in order to
select an alternative bridge 40 for the identified monitor patch
20,
[0102] The process 1000 then proceeds to decision state 1050 in
which it is determined whether there is another monitor patch 20
associated with the selected bridge 40 determined to be inoperable
at the decision state 1010. If it is determined at the decision
state 1050 that there is no other monitor patch 20 associated with
the inoperable bridge 40, the operation 1000 ends at state 1003. On
the other hand, if it is determined at the decision state 1050 that
there is another monitor patch 20 associated with the inoperable
bridge 40 (YES) (the monitor patch 20E for the bridge 40D in the
above example), the process 1000 loops back to the decision state
1030 in which it is determined where there are one or more
alternative bridges 40 for the other monitor patch 20 and then to
the selection operation 1040 and decision state 1050. The loop is
repeated until it is determined at the decision state 1050 that
there is no other monitor patch 20 associated with the inoperable
bridge 40 in which case the process 1000 ends at state 1003.
[0103] In certain aspects, the knowledge of locations of monitor
patches (e.g., 20A-O of FIGS. 4A and 4B) can be used for tracking
patients (e.g., 10A-O) wearing the monitor patches 20 in a
healthcare facility (e.g., hospital). As discussed above with
respect to FIG. 7, a surveillance server (e.g., 60 of FIG. 1) can
track locations of monitor patches 20 by keeping and updating
database 372 comprising information indicative of the monitor
patches 20 and their linkable and selected bridges 40 based on
messages received from various bridges 40. Therefore, assuming that
the locations of various bridges 40 in the facility and the names
of patients 10 to whom the monitor patches 20 are assigned are
known, locations of the patients 10 can also be tracked.
[0104] FIG. 11 is a flowchart illustrating a process 1100 for
determining locations of patients 10 in a healthcare facility
according to certain aspects of the present disclosure. The process
1100 begins at start state 1101 and proceeds to operation 1110 in
which a surveillance server 60 receives a signal comprising
information relating to a monitor patch 20 attached to a patient 10
from a selected bridge 40 for the monitor patch 20. The signal can
be, for example, one of the messages 800A and 800B discussed above
with respect to FIGS. 8A and 8B. After receiving the signal,
surveillance server 60 can update database 372 such as the ones
shown in FIGS. 4A and 4B as discussed above with respect to FIG. 7.
In certain embodiments, the signal is generated by the bridge 40 in
response to a newly established communication link between the
bridge 40 and the monitor patch 20 trigged by the patient 10 being
moved into her new patient room. In other embodiments, the signal
is generated by the bridge 40 in response to a query signal sent to
the bridge 40 by the surveillance server 60.
[0105] The process 1100 proceeds to operation 1120 in which a
patient to whom the monitor patch 20 is attached is identified. In
certain embodiments, the identification operation includes control
software running in the surveillance server 60 accessing a database
such as the one shown in FIG. 12A that lists monitor patches 20
(first column) and their assigned patients 10 (second column). In
other embodiments, the received signal includes information
indicative of the patient 10 (e.g., the patient ID), and the
control software extracts the information from the signal. The
process 1100 proceeds to operation 1130 in which location of the
patient 10 is determined. In certain embodiments, the operation
1130 includes the control software accessing a database such as the
one shown in FIG. 12B that lists locations of various bridges 40 in
the facility. In other embodiments, the received signal includes
information indicative of the location of the bridge 40 that sent
the signal, and the control software extracts the information from
the signal. In some embodiments, the determined location (e.g.,
"Room 3") is displayed on a display associated with a hospital
system (e.g., the workstation 100 of FIG. 1). Alternatively, the
display can graphically indicate the patient location on a hospital
map such as the ones shown FIGS. 4A and 4B.
[0106] The foregoing description is provided to enable any person
skilled in the art to practice the various embodiments described
herein. While the foregoing embodiments have been particularly
described with reference to the various figures and embodiments, it
should be understood that these are for illustration purposes only
and should not be taken as limiting the scope of the claims.
[0107] The word "exemplary" is used herein to mean "serving as an
example or illustration." Any aspect or design described herein as
"exemplary" is not necessarily to be construed as preferred or
advantageous over other aspects or designs.
[0108] A reference to an element in the singular is not intended to
mean "one and only one" unless specifically stated, but rather "one
or more." The term "some" refers to one or more. Underlined and/or
italicized headings and subheadings are used for convenience only,
do not limit the invention, and are not referred to in connection
with the interpretation of the description of the invention. All
structural and functional equivalents to the elements of the
various embodiments of the invention described throughout this
disclosure that are known or later come to be known to those of
ordinary skill in the art are expressly incorporated herein by
reference and intended to be encompassed by the invention.
Moreover, nothing disclosed herein is intended to be dedicated to
the public regardless of whether such disclosure is explicitly
recited in the above description.
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